Compensating device.



J. E. ENGLESSON. COMPENSATING DEVICE. APPLIGATION FILED JUNE 27, 1912.

Patmed 31111.26

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JOHN ELOV ENGLESSON, OF KARLSKRONA, SWEDEN, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

Specification of Letters Patent.

Patented Jan. 26, A1915..

Application led .Tune 27, 19112. Serial No. 706,312.

To all whom t may concern.'

Be it known that I, Joni: ELov ENGLEssoN, a subject of the King of Sweden, residing at Karlskrona, Sweden, have invented a certain new and useful Improvement in Compensating Devices, of which the follow ing is a specification. ,Y

This invention relates to compensating devices for indirect governors of any prime movers. Y

The object of the invention is to secure a compensation of the primary compensating device, such as a floating lever, to reduce the percentage of the speed variation between full load and no load. I

The invention is disclosed herein as gen i erally applied, but the invention has actually been applied to a hydraulic prime mover.

AQclear conception of one embodiment of the invention may be had by referring to the 4drawing accompanying and formingv a` part of this specication in which like reference characters designate the same or similar parts in the various views.

In the drawing, Figure l is an elevation of the general application of the invention. Fig. 2 is a central vertical section enlarged, of the compensating device. Fig. 3 is a central vertical section enlarged, of the dashpot piston. Fig. 4 is a detail sectional view of a fragment of the compensating casing showing the means for connecting to the spring casing.

Referring 'to the drawing, especially Fig.

1, the governor 1 is connected to the usual` floating lever 2, which is connected by a rod 3 to the distributing valve in valve casing 4 mounted on the support 51. The distributing valve distributes through pipes 5, 6, to servo-motor 7, the piston rod 8 of which is connected to any main gate or throttle valve or other controlling means of any prime mover, not shown. The piston rod 8 is pivotally connected at its upper end by link 9 to T-lever 10, pivotally Vmounted on frame 51. rIlle T-lever 10 is connected by link 11 to the lower end of the compensating casing 12, vertically slidable in a lateral extension of the frame 51. A The lower portion of the compensating casing 12 is normally filled with oil or other fluid. Y'Ihe piston rod 13 of the compensator is pivotally and laterally slidably connected to the left end of the floating lever 2. T-lever 14 is pivotally and laterally slidably connected to frame 51 at the right-hand end of the horizontal portion of the T, and at the left-hand end is piv otally connected to the spring casing 15 in the compensator, see Figs. 1 and 4. The lower end of the T-lever 14 is slidable in crosshead l16 pivotally adjustably mounted in vertical guideway 17 of T-lever 10.

r The connections between the compensating and spring casings 12, 15, and the servomotor piston rod 8, are such that as the rod 8 moves to open or close the main gate, the casings 12, 15, are simultaneously moved in a vertical direction. The rate, extent and direction of the motion of the spring casing l5 is variable and depends upon the position of the crosshead 16 relative to the guideway 17 of the T-lever 10.

Referring more specifically to Figs. 2, 3 and 4 of the drawing, the compensator casing 12 has fitted therein spring casing 15 and dash-pot piston 18. The spring casing 15 carries a spring 19 under compression, which bears directly against washers 20, 20, themselves bearing against the inner ends of the spring casing. The piston rod 13 has fixed thereon collar 21 at a point ,normally a short distance below the lower approximately equal to twice the weight of piston 18 and connected parts, so that these parts will be poised in spaced relation from the washers 20. The piston 18 has a small through-port 26 which is preferably adjustable by a set-screw 62, see Fig. 3. The piston 18 carries relief valves 27, 28, respectively, held to their seats by springs 29, 30, fastened at their ends to nuts 31, 32, adjustable in the through-ports 33, 34. The nuts 31, 32 are perforated to permit a limited flow of fluid therethrough when the valves 27, 28, are olf their seats.

The operation of the device is as follows: `When the speed of the prime mover remains constant, the piston rod 13 will be held 1n poised position spacing the collar 21 from the lower washer 20 and the spool 23 from the upper washer 20 as described.

For small speed changes of the prime mover', the governor 1 will have asmall range of movement from normal position. This movement will be compensated in the usual way through the floating lever 2, and

the piston rod 13 will have the correspond-y ing small motion, but only up to a point where the collar 21 would come in Contact with lower washer 20, or spool 23 would come in contact with the upper washer 20. Such small movement will be substantially exactly communicated to the piston rod 13 which will thereafter slowly be returned by reason of the oil in the dash-pot passing from one side of the piston 18 to the other through the small port 26. For speed changes which are great, the casing 12 is moved enough to cause the piston rod 13 to more to a greater extent than that provided for by the spaced relation as to the washers 20. The rod 13 will be moved, say upwardly for example, until collar 21 comes into contact with the lower washer 20, after which it will continue in its upward motion by compressing spring 19 from the lower end. The spring casing 15 is in the meantime move dat a slower rate and to a considerably less extent, the amount of motion of the casing 15 depending upon the position of the crosshead 16 upon the vertical leg of the T-lever 14, which position determines the angle of swing of the lever lei-and hence the rate, extent and direction of movement of the casing 15. During the compression of the spring, however, the compression of oil underneath piston 18 will be so great as to cause relief valve 27 to open. The piston rod 13 will now have moved to the extent required to return the distributing valve to mid-position and the servo-motor motion ceases. The spring 19 will now return the lower washer 20 and "i the piston rod 13 by Contact with collar 21. Thislreturn will lue-comparatively quickly accomplished by reason of the relief valve 27 remaining open because a thoroughfare additional to that of a small port 26 has been established through piston 18. After the lower washer 20 seats on spring casing 15, the return of piston rod 13 is completed by the weight of the piston and connected parts as heretofore described, this completion of the return being accomplished with the relief valve 27 closed.

If a relatively great speed change takes place in the opposite direction, the reverse operation of the mechanism will take place. The downward motion of the casing 12 causes the piston 18 and rod 13 to move downwardly until the spool 23 comes in contact with the upper washer 20. Continued downward motion of the casing 12 suficimitlv reduces the pressure of the oil .tact with the spool through the upper washer 20.- This return will be comparatively quickly accomplished, as the relief valve 28 in addition to the constantly open passage 26, remains open. After the upper washer 20 seats on the spring casing 15, the return of the piston rod 13 is completed vby the action of the spring 25. This completion of the return stroke of thev piston rod 13 is accomplished with the relief valve 28 closed. l

It will thus be seen that with a large variation in the load of the prime mover the speed may be brought back to normal very quickly with tl e use of the present invention. It will al o be seen that a practically rigid connection between the gates of the prime mover and the governor floating lever is provided which will cause the beginning of each impulse of the gates to act quickly and positively upon the floating lever to compensate for effect produced upon the distributing valve. It should also be noted that with the present invention communication from one side of theppiston 18 to the other is never closed oifentirely, this feature permitting the piston 18 and rod 13 to return to its exact mid-position within the spring casing 15.

It should be understood that it is not desired to be limited to the exact details of construction shown and described, for obvious 'modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent,-

1. In a governor for prime movers, a servo-motor, a distributing valve vfor said servo-motor, speed responsive means for actuating said distributing valve to controlthe power applied to the prime mover, means connecting said servo-motor and said distributing valve to compensate the actionof said speed responsive means upon said distributing valve, said means including a casv ing adapted to contain a liquid, a piston within said casing, means for permitting passageof Huid from one side of saidY piston to the other, and means for partially restricting the passage of said fluid.

2. In a governor for prime movers, a servo-motor, a distributing valve for said servo-motor, speed responsive means for actuating said distributing valve to control the power applied to the Aprime mover, means connecting-said servo-motor and said distributing valve to 4compensate the action of said speed responsive means upon said distributing valve, said means including a casing adapted to contain a liquid, a piston within said casing, means for permitting passage of fluid from one side of said piston to the other, and means permitting a sudden increase in the said passage of fluid.

3. In a governor for prime movers, a

servo-motor, a distributing valve for said servo-motor, speed responsive means for actuating said distributing valve to control the power applied to the prime mover, means connecting said servo-motor and said distributing valve to compensate the action of said speed responsive means upon said distributing valve, said means including a casing adapted to contain a liquid, a piston within said casing, means for permitting passage of Huid from one side of said piston to the other.- for slow motion of said piston, and means for increasing said passage for quick motion of said piston to the position of influence by said slow motion means.

4. In a governor for prime movers, a

of two witnesses.

servo-motor, a primary compensator for the governor motion, and a secondary compensator for the primary compensator, said secondary compensator including a plurality of means, one for efecting uick compenpensation. 4

5.111 a governor for prlmel movers, a

servo-motor,a primary compensator for the governor motiona secondary compensator for the primary compensator, said secondary compensator including a plurality of means, one for effetin, yquick compensation and the other for e ecting slow compensation, and spring means for effecting the position-, ing of the'secondary compensator elements to divide the return stroke thereof into quick and slow parts.

In testimony whereof, the signature of the inventor' is affixed hereto in the presence J. ELOV ENGLESSON. Witnesses:`

CEAS. L. BYRON, W. H.. LIEBER.

3o sation and the other for elfectlng slow com- 

